In modern medicine there is an increased tendency in utilizing elements from blood in the treatment of ailments or for diagnostic use. One method of extracting elements from blood such as thrombocytes (platelets), leukocytes (white blood cells) or blood plasma is by fractionating whole blood by placing a container of whole blood in a centrifuge where the blood becomes separated into its component parts.
The component parts may be utilized for specific treatment or diagnostic purposes for the human body, where the specific components may be administered to a patient that might need a dosage of thrombocytes, in case that a patient does not have enough thrombocytes in case of a haemorrhage. Another use for the component parts of whole blood may e.g. be in wound treatment, where the whole blood may be introduced into a container where the blood is induced to coagulate and where upon a specific centrifugation regime the components of the whole blood have been concentrated into a blood product.
WO 2010/020254 discloses how to prepare a multi-layered blood product by centrifugation of blood, where the blood is placed in a container and the coagulation of the blood is activated during or after placing the blood in the container. During the centrifugation, the components of the blood are separated from each other and produce a three-layered blood product, which in sequential order comprises a first layer, which substantially comprises fibrin, a second intermediate layer, which substantially comprises thrombocytes, and a third layer, which substantially comprises leukocytes.
WO 2012/037942 discloses a container to be used for preparing a multi-layered blood product by centrifugation, where said container comprises a filling opening as well as a filter device which is slidable inside the container. The filter device comprises a planar mesh and a supporting buoyancy body, where the filter device is adapted to collect the multi-layered blood product on or above the mesh.
In WO 2010/020254 and WO 2012/037942 there is a requirement that the whole blood and/or the container holding the whole blood has to be centrifuged a certain amount of time at a certain speed in order to ensure that the blood product has been formed inside the container.
However, as one of the important factors for the provision of the blood product is the coagulation of the whole blood inside the container, it has been observed that the coagulation time of whole blood may vary significantly from one donor to another. This variation in coagulation time affects the centrifugation process of the container holding the whole blood, as the preparation time of the blood product may differ considerably for two different blood donors. It is also to be recognised that other factors, such as age, medicaments, diet and health of the donor can affect the preparation time of the blood product using a centrifuge.
Thus, the medical professionals that are preparing a blood product, such as the blood product disclosed in WO 2010/020254, do not have any methods for determining the exact amount of time that is necessary at a certain speed to ensure that the blood product is ready for use for wound healing, prior to the centrifugation process.
The centrifugation process of the blood product is often performed using a benchtop or a table centrifuge that is provided with a rotor that rotates along a vertical axis, where the containers are arranged in a radial direction away from the rotational axis. The containers are often either fixed at a certain angle, or they may be arranged to be positioned at one angle to the rotational axis when the rotor is stationary and to rotate in a direction towards a plane that is perpendicular to the rotational axis when the rotor has been accelerated into rotational motion, i.e. swinging head centrifuges or swing-out (buckets) centrifuges. Such rotational movement of the container ensures that he centrifugal force during centrifugation may be directed along the longitudinal axis of the container, ensuring that the particles density of the particles inside the whole blood is in a sequential order, where the particles having a higher density is at a distal end of the container, while the particles having smaller densities are concentrated at a more proximal position in the container. The terms proximal and distal defined in relation to the rotational axis of the centrifuge, where the distal end of the container is the part of the container that is arranged farther away from the rotational axis during centrifugation, while the proximal end is arranged closed to the rotational axis.
For safety reasons, a benchtop or a table centrifuge is provided with a lid, so that the rotating motion of the rotor cannot injure or harm any persons that are in the vicinity of the centrifuge during operation. Thus, this often means that the blood samples or the whole blood inside the container cannot be inspected during centrifugation, as there is no direct visual access to the content of the container. Furthermore, as the centrifuges can operate at a rotational speed that may be up to 4000 RPM, 8000 RPM or more, i.e. approximately 66-132 revolutions per second or more, it may be difficult or even impossible to visualise the state of the contents of the container during rotation with the bare eyes, even if there would be direct visual access to the contents of the container.
Furthermore, as coagulation occurs over a certain period of time, where the termination of the coagulation is indicated by the lack of change in optical density, the process has to be observed continuously during the process in order to get the optimal result of the coagulation process.
Thus, the medical professionals preparing a blood product do not have any methods or tools to recognise when the centrifugal process of the container has been carried out enough to prepare the blood product sufficiently for use. Thus, the medical professionals have tried to figure out an amount of time that is sufficient for most users, and apply this qualified guessed amount of time to the centrifugal process. As an example, if the predetermined amount of time is 10 minutes, this amount of time may be sufficient for some donors, while for other donors the blood has to be reintroduced to the centrifugal process after removing the container from the centrifuge and visually inspecting the contents. For some donors, the blood product may be ready within 2-5 minutes, while for other donors the blood product may be ready within 15-20 minutes or even more, of the initial centrifugation.
Thus, if it is necessary to prepare multiple blood products for the wound treatment of a donor, each minute of wasted centrifugation and/or visual inspection may be multiplied by the amount of products to be prepared by subsequent centrifugation processes. Thus, there is a need to increase the efficiency of the centrifugal process.